Finally, Alginate epimerases (and polysaccharide epimerases) are part of CAZypedia – Thanks to Margrethe 😊

From Cazypedia news

22 September 2020: Like PLs, but different: We are happy to announce the completion of a new Lexicon page on Polysaccharide epimerases today. Margrethe Gaardlos spearheaded the composition of this new page, with input from co-author Anne Tøndervik and Responsible Curator Finn Lillelund Aachmann. Although they are not categorized into families in the CAZy system, Polysaccharide epimerases bear a lot of structural and mechanistic similarity to Polysaccharide Lyases: Instead of catalyzing an elimination reaction to break poly-uronic acid chains, Polysaccharide epimerases simply use the first part of the PL mechanism to remove and re-add the C-5 proton. The resulting change in the configuration of the C-6 carboxylate has major impacts on polysaccharide structure and properties. The Norwegian team has done a tremendous job in capturing the broad history of these enzymes, including their diverse substrate specificities and structures (and over 130 references!), which you can read all about here. (We also thank Mirjam Czjzek for championing the inclusion of the “PEs” in CAZYpedia.)